1. Field of the Invention:
The present invention relates to a solenoid-operated valve actuating controller, and more particularly to a solenoid-operated valve actuating controller for actuating a solenoid-operated valve in a rated actuation mode and a power saving actuation mode.
2. Description of the Related Art:
Heretofore, one type of general solenoid-operated valve actuating controller has been disclosed in Japanese Laid-Open Utility Model Publication No. 5-47334, for example.
The disclosed solenoid-operated valve actuating controller comprises a DC power supply, a switch, an actuating coil of a solenoid-operated valve, and an operating transistor, which are connected in series with each other. The solenoid-operated valve actuating controller also includes a control transistor, for controlling the operating transistor, connected in parallel with the operating transistor.
The amount of electrical energy supplied to the actuating coil of the solenoid-operated valve is digitally controlled in order to eliminate drawbacks of a transistor-controlled system, or more specifically, to eliminate drawbacks such as temperature susceptibility, etc., and also to make the solenoid-operated valve actuating controller versatile in use.
The conventional solenoid-operated valve actuating controller also has a voltage-dividing resistor connected to the actuating coil for reducing power consumed by the solenoid-operated valve.
However, the voltage-dividing resistor of the conventional solenoid-operated valve actuating controller must have a resistance value that depends on the electric current required by the actuating coil. Since it is necessary for the rating of the voltage-dividing resistor to be determined in view of heat generated thereby as well as other factors, the size of the voltage-dividing resistor usually tends to be large.
In addition, efforts in recent years to reduce the size of solenoid-operated valves have made it difficult to mount a voltage-dividing resistor on the actuating coil of the solenoid-operated valve.